Polaroid Corporation

Aprilis, Inc.

Stx Aprilis, Inc.

Identix Corporation

Richard T Ingwall

David A Waldman

Eric S Kolb

Russell A Gaudiana

Richard A Minns

William J Cumming

Daniel Henri Raguin

John S Berg

Parag G Mehta

Cheryl P Petersen

Mark A Troll

Herbert L Fielding

Pradeep K Dhal

David L Kent

Phillip H Malyak

Vincent Fedele

Larry Takiff

Joby Joseph

Erdem A Cetin

Howard G Schild

Michael Glenn Horner

M Glenn Horner

Duncan H Whitney

Rod Hopwood

YajPaul Panchu

Daniel H Raguin

An apparatus and a method for acquiring an image of skin topology. The apparatus comprises at least one light source, configured to form a source beam; at least one illuminating diffractive optical element (DOE) disposed in the optical path of the source beam, configured to diffract the source beam, thereby forming an illuminating beam; a skin contact surface, disposed in the optical path of the illuminating beam, configured to at least partially reflect the illuminating beam at regions of the boundary between the skin contact surface and skin that are not in contact with the skin contact surface, thereby forming a reflected beam; at least one imaging diffractive optical element (DOE), disposed in the optical path of the reflected beam, configured to diffract the reflected light beam, thereby forming an image beam; and a sensor array, configured to receive at least a portion of the image beam and thereby to detect the acquired image.

Diffractive imaging system and method for the reading and analysis of skin topology

An apparatus for image acquisition of topological features of the surface of skin. The apparatus comprises a waveguide, having an entrance edge and top and bottom surfaces; a light source, configured to direct a light beam at the entrance edge of the waveguide; a skin contact layer, disposed at or near the top surface of the waveguides; a holographic optical element (HOE), disposed at the top or at the bottom surfaces of the waveguide, configured to diffract the light beam incident from the light source to the skin contact layer; a sensor array, configured to detect light reflected from the surface of skin in contact with skin contact layer; and means for compensating for changes in the Bragg matching condition of the HOE due to temperature.

Acquisition of high resolution biometric images

A holographic optical filter that includes an optical recording medium for storing several multiplexed reflection holograms that are formed by successive interference between two or more collimated object beams with a common collimated reference beam. The object beams are incident to the recording material at a series of angles chosen to provide reflection efficiency over the desired filed of view at the specified wavelength.

Holographic filter with a wide angular field of view and a narrow spectral bandwidth

A Bragg grating that has an average index of refraction that changes with temperature to compensate for variations in grating spacing caused by temperature changes.

Temperature compensation of Bragg reflection gratings

Disclosed is a photopolymerizable holographic recording medium for data storage that comprises colloidal metal, and which exhibits a threshold for a second stage polymerization which is substantially insensitive to the light used for both forming holograms and interrogating the medium during servo and/or read events. Also disclosed is a method of preparing said photopolymerizable holographic recording medium. Also disclosed is a method for preparing a colloidal without additives in a viscous medium.

Data storage medium comprising colloidal metal and preparation process thereof

A hybrid data storage system comprising at least one memory system and at least one holographic drive, data being transmitted between the holographic drive and the memory system. At least one holographic drive writes data to a first holographic recording medium, and reads the written data from said first recording medium and from at least one other holographic recording medium.

Hybrid data storage system

An apparatus and method that produces recording media using at least two platens. A first platen is movable relative to a second platen, and each platen has respective first and second support surfaces onto which substrates are placed, the first and second substrates each having inner and outer longitudinal surfaces. A centering device aligns the respective substrates relative to a one or more reference positions, a positioning system provides a degree of parallelism between the outer longitudinal surfaces of each of the substrates and produces a desired gap between the inner longitudinal surfaces of the substrates, and a dispensing unit which emits a liquid medium within the gap between inner longitudinal surfaces of the substrates.

Method and apparatus for producing optical recording media with accurately parallel surfaces

A holographic recording medium comprises an acid generator capable of producing an acid upon exposure to actinic radiation; a binder; and at least one monomer or oligomer capable of undergoing cationic polymerization initiated by the acid produced from the acid generator. This recording medium is not subject to the disadvantages (for example, oxygen sensitivity) associated with radical-polymerized prior art holographic recording media.

Holographic medium and process for use thereof

Electroluminescent devices have, as the active layer, a polymer having a chain comprising a plurality of electroluminescent groupings, adjacent pairs of the electroluminescent groupings being connected via two benzene rings linked to each other only by a single covalent bond, at least one of the benzene rings bearing, at a position ortho to the covalent bond, a substituent of sufficient size that the length of the bond connecting the two benzene rings is not less than 1.495 Angstroms. Preferred electroluminescent groupings comprise a chain of three or more para-phenylene groups connected to one another by amide, carboxy, ester, urea, urethane or vinyl groups. The polymers have a fixed conjugation length with predictable electroluminescent properties.

Electroluminescent devices comprising polymers, and processes for their

An electroluminescent polymer comprises a main chain and a plurality of side chains, each of the side chains comprising an electroluminescent group and a flexible spacer connecting the electroluminescent group to the main chain, the spacers and the main chain being such that the electroluminescent groups are not conjugated with one another. The nature of the main chain and the spacer groups can be varied to enhance solubility, film-forming ability and other characteristics of the polymer, without significantly changing the electroluminescent properties of the polymer.

Electroluminescent polymers, processes for their use, and

Electroluminescent devices have, as the active layer, a polymer having a chain comprising a plurality of electroluminescent groupings, adjacent pairs of the electroluminescent groupings being connected via two benzene rings linked by only a single covalent bond, at least one of the benzene rings bearing, at a position ortho to the covalent bond, a substituent of sufficient size that the two benzene rings are essentially not conjugated with each other. Preferred electroluminescent groupings comprise a chain of three or more para-phenylene groups connected to one another by amide, carboxy, ester, urea, urethane or vinyl groups. The polymers have a fixed conjugation length with predictable electroluminescent properties.

Composite holograms are disclosed wherein microvoids between the holographic interference fringes are filled with a liquid crystal. The diffraction efficiency and other holographic properties of such composite holograms may be varied by external stimuli, e.g., application of an electric field of thermal energy.

Volume phase hologram with liquid crystal in microvoids between fringes

Volume phase holograms and other holographic elements are disclosed which include microscopic areas of a material having an index of refraction different from that of the holographic fringes.

Holograms

Novel photopolymerizable compositions are provided which comprise a dye sensitizer, a branched polyethylenimine as a polymerization initiator and a free radical polymerizable ethylenic unsaturated monomer. In the preferred embodiments, the branched polyethylenimine is used in combination with lithium acrylate. This combination provides dry coatings which may be stored for extended periods prior to being activated for imaging, and which produce volume holograms of very high resolution and diffraction efficiency.

Growing community of inventors

Newton, MA, United States of America

Richard T Ingwall